Effect of porosity and tension–compression asymmetry on the Bauschinger effect in porous sintered steels

Deng, Xin; Piotrowski, George; Williams, Jason; Chawla, Nikhilesh

doi:10.1016/j.ijfatigue.2005.06.041

Cited by 31 publications

(18 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Thus, the coarser microstructure in the furnace-cooled samples resulted in decreased resistance to dislocation motion. The weak dependence of ultimate tensile strength on 13 and the analytical prediction by Ramakrishnan and Arunachalam, 20 showing reasonable agreement between experiment and prediction. cooling rates may be explained by the fact that as the ultimate tensile strength is approached, the amount of plastic deformation is very large, and stress-relaxation mechanisms are predominant.…”

Section: Tensile Behaviorsupporting

confidence: 69%

“…Samples were heated at 240°C (approximately 20°C above the eutectic point of the solder) for 20 sec and cooled in different cooling media: water, air, and furnace. The cooling rate was measured from peak temperature to 150°C because previous work by the authors 12,13 has shown that no significant change in microstructure is observed below this temperature (for the time scales involved in cooling the solder). Cooling of the solder by water quenching, air cooling, and furnace cooling yielded cooling rates of 24°C/sec, 0.5°C/sec, and 0.08°C/sec, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…5). Measurements by resonant ultrasonic spectroscopy, reported by Deng et al, 13 are also presented for comparison. As expected, a gradual decrease in Young's modulus with increasing porosity was observed.…”

Section: Tensile Behaviormentioning

confidence: 99%

See 2 more Smart Citations

Effects of cooling rate on the microstructure and tensile behavior of a Sn-3.5wt.%Ag solder

Ochoa

Williams

Chawla

2003

Journal of Elec Materi

179

View full text Add to dashboard Cite

The tensile behavior and microstructure of bulk, Sn-3.5Ag solders as a function of cooling rate were studied. Cooling rate is an important processing parameter that affects the microstructure of the solder and, therefore, significantly influences mechanical behavior. Controlled cooling rates were obtained by cooling specimens in different media: water, air, and furnace. Cooling rate significantly affected secondary dendrite-arm size and spacing of the Sn-rich phase, as well as the aspect ratio of Ag 3 Sn. The Sn-rich dendrite-arm size and spacing were smaller for water-cooled specimens than for air-cooled specimens. Furnace cooling yielded a nearly eutectic microstructure because the cooling rate approached equilibrium cooling. The morphology of Ag 3 Sn also changed from spherical, at a fast cooling rate, to a needlelike morphology for slower cooling. The changes in the microstructure induced by the cooling rate significantly affected the mechanical behavior of the solder. Yield strength was found to increase with increasing cooling rate, although ultimate tensile strength and strain-to-failure seemed unaffected by cooling rate. Cooling rate did not seem to affect Young's modulus, although a clear correlation between modulus and porosity was obtained. The mechanical behavior was correlated with the observed microstructure, and fractographic analysis was employed to elucidate the underlying damage mechanisms.

show abstract

Section: Tensile Behaviorsupporting

confidence: 69%

Section: Methodsmentioning

confidence: 99%

See 1 more Smart Citation

Effects of cooling rate on the microstructure and tensile behavior of a Sn-3.5wt.%Ag solder

Ochoa

Williams

Chawla

2003

Journal of Elec Materi

179

View full text Add to dashboard Cite

show abstract

“…This difference is thought to be due to structural differences, principally as a result of the large windows in the cell walls that are present in the tapped structures (although it should be noted that residual salt in the mixed samples may contribute to the strength and stiffness). The fit to the open cell model is better for samples made by tapping and for the stiffness data, supporting the increased contribution of the cell walls to the strength for samples made by mixing (with no large windows in the cell walls) and the more harmful effect of cell wall porosity on stiffness [32].…”

Section: Mechanical Testingmentioning

confidence: 60%

Porous poly-ether ether ketone (PEEK) manufactured by a novel powder route using near-spherical salt bead porogens: Characterisation and mechanical properties

Siddiq

Kennedy

2015

Materials Science and Engineering: C

View full text Add to dashboard Cite

Porous PEEK structures with approximately 85% open porosity have been made using PEEK-OPTIMA® powder and a particulate leaching technique using porous, near-spherical, sodium chloride beads. A novel manufacturing approach is presented and compared with a traditional dry mixing method. Irrespective of the method used, the use of near-spherical beads with a fairly narrow size range results in uniform pore structures. However the integration, by tapping, of fine PEEK into a pre-existing network salt beads, followed by compaction and "sintering", produces porous structures with excellent repeatability and homogeneity of density; more uniform pore and strut sizes; an improved and predictable level of connectivity via the formation of "windows" between the cells; faster salt removal rates and lower levels of residual salt. Although tapped samples show a compressive yield stress > 1 MPa and stiffness > 30 MPa for samples with 84% porosity, the presence of windows in the cell walls means that tapped structures show lower strengths and lower stiffnesses than equivalent structures made by mixing.

show abstract

“…The differences presumably arise from higher strength of the alloy powder used in this study and from the porosity present in the cell walls. Porosity in PM materials is much more detrimental to the stiffness than the strength in compression [15] and results in a much larger decreases in stiffness than is predicted by established relationships between porosity and stiffness for foams [15,16]. It is, therefore, to be expected that the foam stiffness will be lower than that for a foam with an equivalent relative density and fully dense struts.…”

Section: Resultsmentioning

confidence: 97%

The manufacture of spherical salt beads and their use as dissolvable templates for the production of cellular solids via a powder metallurgy route

Jinnapat

Kennedy

2010

Journal of Alloys and Compounds

View full text Add to dashboard Cite

Effect of porosity and tension–compression asymmetry on the Bauschinger effect in porous sintered steels

Cited by 31 publications

References 31 publications

Effects of cooling rate on the microstructure and tensile behavior of a Sn-3.5wt.%Ag solder

Effects of cooling rate on the microstructure and tensile behavior of a Sn-3.5wt.%Ag solder

Porous poly-ether ether ketone (PEEK) manufactured by a novel powder route using near-spherical salt bead porogens: Characterisation and mechanical properties

The manufacture of spherical salt beads and their use as dissolvable templates for the production of cellular solids via a powder metallurgy route

Contact Info

Product

Resources

About